Question: Simplify the following expression: ${-2(9+3k)-(-2k+7)}$
Answer: Distribute the ${-2}$ into the first set of parentheses: $ {-2(}\gray{9+3k}{)} - (-2k+7) $ $ {-18-6k} - (-2k+7) $ The minus sign in front of the parentheses means we multiply each term inside the parentheses by ${-1}$ $ -18-6k {-1(}\gray{-2k+7}{)} $ $ -18-6k + {2k-7} $ Rewrite the expression to group the ${k}$ terms and numeric terms: $ {-6k + 2k} {-18 - 7}$ Combine the ${k}$ terms: $ {-4k} {-18 - 7}$ Combine the numeric terms: $ {-4k} {-25}$ The simplified expression is $-4k-25$